Gas and air operated valve



Dec. 8, 1942.

W. J. M GOLDRICK GAS AND AIR OPERATED VALVE Filed Feb. 12, 1940finnenfor William "J. Mfioldrick Patented Dec. 8, 1942 I UNITED STATE SPATENT OFFICE Gas AND AIR OPERATED VALVE .William J. McGoldrick,

signor to Minneapoli Company, Minneapolis,

Delaware Minneapolis, Minn,, ass-Honeywell Regulator Minn., acorporation of Application February 12, 1940, Serial No. 318,419

4 10 Claims.

The present invention relates tothe operation and control of valves,particularly in gas fired combustion systems employing forced draft. Insuch systems diaphragm type gas control valves are commonly used and myinvention deals primarily with a novel and improved arrangement foroperating such a valve in the type of system referred to.

In the control of forced draft combustion systems employing gaseous fuelit is important that positive means be provided for actuating the fuelvalve at the proper times and in the proper manner.

' It is the object of my invention to provide an arrangement offeringassurance of the attain-" Another object of my invention is to providean air operated diaphragm valve in combination with means providing forquick and positive closing of the valve.

Another object of my invention is to provide an air operated diaphragmvalve in combination with means for applying gas pressure to one side ofthe diaphragm to assist in operation of the valve. v

The single flgure of'the drawing represents a gas fired forced draftcombustion system embodying my invention therein.

Referring tothe drawing, numeral l designates a gas fired furnace ofusual type there being located within the furnace a gas burner llthrough which gas is supplied through a conduit l2. Interposed in theconduit I2 is a diaphragm type gas valve indicated generally at l3.Conduit l2 aheadof th valve [3 may communicate with any suitable sourceof fluid fuel such as gas. Located adjacent the burner H is a smallpilot burner i4, the purpose of which is to ignite the flame of the mainburner II and gas is continuously supplied to the pilot burner l4 bymeans of a tube I5 communicating with the conduit l2 ahead of the valvel3. Numeral l6 designates generally a safety pilot comprising a bimetaleleth flame of the pilot burner and flexed into engagement with a fixedelectrical contact l8.

The furnace I0 is of a forced draft type, numeral 2| designating aforced draft fan driven by an electrical motor and having a dischargeduct 22 communicating with the lower part of the furnace.

The body portion of the valve l3 has an inlet at 23 and an outlet at24,there being a passageway through the valve controlled by a valv member25 to which is connected a valve stem 26. The

upper part of the valve l3 comprises a conically shaped portion 21having a flange 28. Numeral 23 designates a dish shaped member having anopening in its lower portion, this member constituting the lower part ofa diaphragm chamber of the valve. The peripheral portions of a sealoffdiaphragm 3| are engaged between the flange 28 of portion 21 and thelower surface of the dish shaped member 29, these parts being securedtogether in any suitable manner. The valve stem 26 extends. through theseal-off diaphragm 3|, and the portions of the seal-off diaphragmadjacent'the valve stem are secured between a pair of collars 32 and 33secured-to the valve stem in anysuitable manner. Numeral34 designates aring shaped member of a size externally as great as the greaterdimension or the flange'of the member 29. The ring 34 is superimposed onthe flange of the member 29 with the peripheral portions ofthe diaphragm35 secured between the ring 34 and the flang of the member 29. Numera136 designates a flanged cover element for the, diaphragm chamber havinga flange of the same size as the ring 34, the flange being in engagement therewith, the flanges, th ring 34 and the peripheral'portionsof the diaphragm 35 all being secured together in any suitable manner.The valve stem 26 passes through the diaphragm 35 and the portions ofthe diaphragm adjacent the valve stem are secured between two discs 31and 38 which are attached to the valve stem in any suitable manner.

Numeral 40 designates a three-way pilot valve of known type operated byan electric solenoid within the housing 4 I The three-way pilot valvecomprises a body portion 42 having an opening 43 therewithin. A channel44 in the body portion 42 communicates with the side of the opening 43and a channel 45 in the body portion 42 communicates with the lower partof the opening 43 and form a seat for the valve member 46. The upperpart of the opening 43 is closed by a plug 41 in screw threadedengagement with the ment I! located was to be normally heated by bodyportion 42 and having a central opening through which extends thestem 48of the valve member 46. The space 43 is in open communication with anopen space above the plug" through the opening in the plug around the-valve stem and the latter space communicates with the conduit |2 aheadofthe valve |3 by means of the tube 49. The valvemember 46 is so shapedas to be able to close off communication through the channel 45 and theopening through the plug 41 also forms a valve seat so that the valvemember 46 canbe moved upwardly to close off communication through theplug 41. When the solenoid within the housing 4| is deenergized thepilot valve is in the position shown. In

this position gas passes through the tube 49,-

through the plug 41 and channel 44 into the space above diaphragm 35,the pressure thus maintaining the valve l3 closed. When the solenoidwithin the housing 4| is energized the valve member 46 is moved upwardlyso as to cut off communication of gas pressure through the plug 4|, andto release the gas from above the diaphragm 35 so that it can passthrough the channels 44 and 45. The channel communicates with anauxiliary. pilot burner-50 by means of atube5l.

, thermostat which may be of a well known..type='comprising a bimetalelement 53 having a movable switch blade 54 attached thereto,-the switchblade'54 cooperatingwith a fixed electrical contact 55. Upon adrop'in-temp'erature to which the thermostat 52 is responsive, to apredetermined value the blade 54 engages-with the contact 55.

In operation, whenever the thermostat 52 makes'contact as described, acircuit is completed for the draftfan as follows: from wire 60 throughthe safety pilot I6, wire 6|, thermostatic element 53, blade 54; contact55, wire 62, wire 63, the fan motor, wire 64 and, wire 65, the wires 60and 65 being connected to any suitable line conductors. At-the same timea circuit is completed for the solenoid within housing 4| as follows:from wire 60 to safety pilot l6, wire 6|,

thermostatic element 53, blade 54, contact 55,

wire .62, wire 66, the solenoid within housing 4| back to wire'65. Assoon as these circuits are completed the draft fan starts in operationand the valve member 46 is moved to its upper position to release thegas from diaphragm 35 as above described. As soon as an appreciableamount of pressure-has been built up in discharge duct 22 thisairpressure is communicated to the chamber on the lower side ofdiaphragm 35 through tube 39 and the diaphragm 35 is lifted ina' mannerto open the valve l3. As soon as the valve is open gas is supplied tothe burner II and heating commences, and continues as long asthethermostat 52 is calling for heat. When the thermostat becomes satisfiedthe above traced circuits are interrupted, the fan stops and the pilotvalve 40 assumes the position shown on the drawing. Inasmuch as the fanand its driving motor have a certain amount of momentum the fan does notstop as soon as its motor is deenergized and therefore the pressure indischarge duct 22 does not immediately disappear. Therefore, withoutother means cooperating to close the valve l3 it would be delayed in 1its closing" action until the pressure had dropped sufliciently withinthe duct 22 and the chamber below the diaphragm 35. To avoid-thiscondition and in order to bring about quick and positive closing of thevalve thethree-way pilot valve 40 is provided to permit gas pressure tobe applied to the upper side of the diaphragm 35 as soon as the fanmotor is deenergized in order to force the diaphragm downward. Thuswhenever the fan motor is deenergized the three-way valve assumes theposition shown on the draw- -ing and gas pressure passes through thetubes 49, the opening in plug 41, space 43 and channel 44 into thechamber about diaphragm 39. The pressure acting on the upper side ofdiaphragm 35 quickly closes the valve preventing any de layed actionwhich would otherwise take place.

From the foregoing those skilled in the art will appreciate that I haveprovided an eflicient and positive acting arrangement whereby adiaphragm valve may be operated by means of a draft pressure from adraft fan, and wherein the valve will be operated with the desired quickmovements by reason of the arrangement for causing gas pressure to acton the upper side of the diaphragm for closing.

The single embodiment of my invention which I have disclosed isrepresentative and the scope of the invention is to be determined not inaccordance with my disclosure but only by the scope of the appendedclaims.

I claim as my invention:

1. In a heating system, in combination, com.- bustion means comprising afurnace having forced draft means, -fuelsupply means including adiaphragm type valve having a diaphragm in a diaphragm chamber, meansfor exposing one side of said diaphragm to draft air pressure foropening the valve. and means for exposing the other side of thediaphragm to fuel at substantially supply pressure, said fuel pressuresupplying the power for closing the valve and maintaining it in closedposition, said last means including means for releasing fuel pressurefrom said other side of the diaphragmto permit the valve to be opened bythe draft air pressure.

2. In a gas fired heating system, in combination, a furnace, forceddraft means and gas supply control means including a gas valve having adiaphragm located within a diaphragm chamber, means for conveying airpressure from said forced draft means to said diaphragm chamber formoving said diaphragm in one direction, pilot valve means controllingthe admission to and release of gas from the chamber on the oppositeside of the diaphragm and control means for starting the forced draftmeans in operation and at substantially the same time operating saidpilot valve .meansto cause gas to be released from said diaphragmchamber.

3. In a gas fired combustion system, in combination, control meanscomprising a. valve having a diaphragm chamber with a diaphragm dividingthe chamber into two parts, forced draft means, means for conveyingdraft air to the space on one side of the diaphragm for opening thevalve, means comprising a pilot valve for admitting gas pressure to andreleasing gas from the space on the other side of the diaphragm; andthermostatic means controlling the forced draft means and said pilotvalve means to substantially simultaneously energize said forced draftmeans and actuate said pilot valve means to release gas from the spaceonthe other side of said diaphragm.

4. In a gas fired heating system, in combination, a furnace, forceddraft means and gas supply control means including a gas valve having adiaphragm located within a diaphragm chamber, means conveying gaspressure to one side of said diaphragm urging said valve in closingdirection, means for cutting off the supply of gas to said one side ofthe diaphragm and releasing the pressure acting thereagainst, and meansconveying draft air from the discharge side of said forced draft meansto the other side of said diaphragm for opening said valve whereby saidvalve is not opened until after the establishment of draft.

5. In a gas fired heating system, in combination, a furnace, forceddraft means and gas supply control means including a gas valve having adiaphragm located within a diaphragm chamber, means comprising athree-way pilot valve for admitting pressure to and releasing pressurefrom one side of the diaphragm, means for conveying draft air from thedischarge side of said forced draft means to the other side of saiddiaphragm for opening said valve, and means comprising a thermostatcontrolling said forced draft means and three-Way pilot valve tosubstantially simultaneously energize said forced draft means andactuate said pilot valve to release pressure from said one side of saiddiaphragm.

6. A fuel control device comprising in combination, a combustionchamber, a conduit for conveying fuel to said combustion chamber, avalve in said conduit for controlling the flow of fuel, a forced draftmeans for supplying com bustion supporting air to said combustionchamber, means, controlling said valve comprising a diaphragm and a pairof diaphragm chambers, means for subjecting one of said chambers topressure for closing said valve and for relieving said pressure when itis desired to open said valve, and means connecting the other chamberwith the pressure created by said forced draft means for opening saidvalve.

'7. A fuel control device comprising in combination a combustionchamber, a conduit for conveying fuel to said combustion chamber, avalve in said conduit for controlling the flow of fuel, a forced draftmeans for supplying combustion supporting air to said combustionchamber, means controlling said valve comprising a diaphragm and a pairof diaphragm chambers, means for alternately subjecting one of saidchambers to pressure and venting it to atmosphere, said diaphragmtending to move said valve to closed position when said one chamber issubjected to pressure, means connecting said other chamber to thedownstream side of said forced draft means whereby said valve may beopened only if said forced draft means is operative, and means forsubstantially simultaneously venting said one chamber to atmosphere andrendering said forced draft means operative.

8. A gas burner control system comprising in combination, a gas supplyconduit for delivering gas under pressure to a burner, forced draftmeans for supplying combustion supporting air,

a valve in said gas supply conduit controlling the flow of gastherethrough, means for actuating said valve including a diaphragm andfirst and second diaphragm chambers, control means for alternatelyconnecting said first chamber to the pressure of gas from the upstreamside of said valve for closing said valve and venting said chamber,means connecting said second chamber to the downstream side of saidforced draft means for opening said valve, and means responsive to ademand for heat for venting said first chamber and energizing saidforced draft means whereby the pressure developed by said forced draftmeans opens said valve.

9. A gas burner control system comprising in combination, a gas supplyconduit for delivering gas under pressure to a burner, forced draftmeans for supplying combustion supporting air, a valve in said gassupply conduit controlling the flow of gas therethrough, means foractuating said valve including a diaphragm and first and seconddiaphragm chambers, a valve stem connecting said diaphragm and valve, asecond diaphragm connected to said valve stem and sealing said secondchamber from the gas pressure at said valve, control means foralternately connecting said first chamber to the pressure of gas fromthe upstream side of said valve for closing said valve and venting saidchamber, means connecting said second chamber to the downstream side ofsaid forced draft means, for opening said valve and means responsive toa demand for heat for venting said first chamber and energizing saidforced draft means whereby the, pressure developed by said forced draftmeans opens said valve.

10; In a gas fired heating system in combination, a gas valve forcontrolling the supply of gas to a burner, a diaphragm located within adiaphragm chamber for moving said valve between open and closedpositions, pilot valve means for controlling the admission of gas to oneside of said diaphragm for closing said gas valve when there is nodemand for burner operation and for bleeding said gas pressure inresponse to a demand for burner operation, means preventing the pressureof said gas from opening said gas valve, and means for admitting airunder pressure from a forced draft means to said other side of saiddiaphragm for causing opening of said gas valve when said pilot valvemeans is in a position to bleed gas from said one side of said diaphragmand said forced draft means is in operation.

WILLIAM J. MCGOLDRICK.

